JPH11348326A - Impact type dot printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form kanji characters of a high dot density and characters of a high print quality at a higher speed by controlling to shorten a power feed time to an excitation coil in accordance with a dot density and to increase a driving frequency on the basis of input information on a type of characters. SOLUTION: A control circuit 10 controls to change a power feed time to an excitation coil 3 and a driving frequency of a print wire 6 via a circuit board 9 in accordance with a dot density. The control circuit 10 controls to shorten the power feed time to the excitation coil 3 and increase the driving frequency as the dot density is higher on the basis of data concerning a type and a quality of characters input through a host computer or keyboard, etc. An input energy to the excitation coil is made smaller as the characters are of a type higher in density and a hit force of the print wire is weakened to enhance the driving frequency. Characters of this type can be printed at a speed as high as possible without any trouble.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an impact type dot printer, and more particularly to an impact type dot printer characterized by recording / writing control according to dot density.

[0002]

2. Description of the Related Art In an impact type dot printer, a printing wire fixed to a tip of a printing lever which is integrated with a plunger by applying a certain voltage to an excitation coil for a certain period of time is magnetically attracted. Is repeated to return the print lever to the standby position by the urging force of the return spring and the reaction force at the time of contact with the return spring. In this case, a character or the like is written.

In general, when the applied voltage is constant, as shown in FIG. 4, the behavior of the printing wire depends on the energizing time t to the exciting coil.
In other words, as the energy applied to the excitation coil is larger, the rise time of the print wire is faster and the collision speed with the recording medium is higher, so that the printing power is stronger and the copying ability can be improved.

However, on the other hand, the energization time t
Not only causes the recording head to generate heat, but also causes the print wire to rebound and cut the magnetic flux Φ.As a result, the print wire returns poorly and catches with the ink ribbon, causing the wire to be caught. This can also cause problems such as cuts.

On the other hand, the number of fonts included in the printer is 10 fonts per inch, that is, 10 cp.
There are i-alphanumeric kana character standard, 12-cpi alpha-numeric kana character elite, and 15-cpi alpha-numeric kana character, and 6.7 cpi standard and 13.8c
There is something called the half-width of pi.

Further, even if the size of the characters is the same, there are fonts such as Gothic and Mincho for kanji, and Roman and courier for alphanumeric and kana characters. Draft giving priority to speed (high speed) and original LQ (high quality, standard, NL
Q).

Further, when characters are formed on a recording medium in a 24 × 12 matrix using a 24-pin printer, if the driving frequency f of the printing wire is 1800 Hz, the carriage traveling speed v in the digit direction is

[0008]

(Equation 1)

Similarly, when the number of dots in the digit direction is set to 36 in order to increase the printing displacement, the traveling speed of the carriage is reduced to one third of the above example.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem.
It is an object of the present invention to provide a new impact-type dot printer that can form kanji having a high dot density and characters having a high print quality at a higher speed without any trouble.

[0011]

That is, according to the present invention, as an impact type dot printer for achieving the above object, the energizing time to the exciting coil is changed according to the dot density based on the information of the input character type. And a control means for controlling the drive frequency to be increased.

[0012]

Embodiments of the present invention will be described below. FIG. 1 shows an impact type recording head applied to the printer of the present invention.

In FIG. 1, reference numeral 1 denotes a general recording head. A print lever 5 is radially arranged on a frame 4 in which the coil cores 2 are arranged in a ring shape so as to face each coil core 2. By selectively energizing the excitation coil 3, the corresponding print lever 5 is magnetically attracted, and the print wire 6 attached to the tip of the print lever 5 is stamped into contact with the recording medium s via the ink ribbon r to perform the engraving. A desired character or the like is formed on the recording medium s by a group of dots.

Reference numeral 10 in the figure denotes a control circuit for controlling the energizing time t to the exciting coil 3 via the circuit board 9 and the driving frequency f of the printing wire 6 to be changed according to the dot density. The control circuit 10 provided in the host computer or the printer so as to form a part of the control circuit for the image forming apparatus has a high dot density based on character type and character quality data input from the host computer or the keyboard. The driving time t to the excitation coil 3 becomes shorter as the dot density becomes higher, and the driving frequency f becomes higher as the dot density becomes higher.

FIG. 2 shows the energizing time t and the driving frequency f for drafting alphanumeric and kana characters having different dot densities and for producing high-quality Chinese characters.

That is, as shown in FIG. 2 (a), as a draft head driving condition for roughly striking alphanumeric characters, the energizing time t1 to the exciting coil 3, ie, the applied energy pw1, is 6 and the collision speed with the recording medium s is increased so that necessary and sufficient printing power and copying ability can be obtained.
The driving frequency f1 is increased by increasing the rebound at the time of collision with the platen 8 and the return delay of the printing wire 4 due to the residual magnetic flux φ to the extent that the movement of the printing wire 4 at the next energization is not affected. While several kana characters can be struck at a normal density and at a normal speed as shown in FIG. 3, the head driving conditions for ejecting a kanji having a high dot density are shown in FIG. As described above, the energizing time t2 to the exciting coil 3 is shortened, that is, the applied energy Pw2 is reduced, the collision speed with the recording medium S is reduced, and the printing force is reduced. By increasing the driving frequency f2 to increase the printing speed, the printing density is reduced and the printing density is averaged as shown in FIG.

In the above-described embodiment, two types of driving conditions for the recording head 1 can be selected: one for drafting alphanumeric and kana characters and the other for high-quality kanji.
For example, using a 24-pin printer, 6 lines, 13 lines, 1 line
When using eight or twenty-seven horizontal rows of pins to draw the alphanumeric kana character draft, kanji half-width, high-definition alphanumeric kana characters, and kanji standard character types, the energizing time for each number of these pins used It is also possible to configure so that t and the driving frequency f can be individually switched.

[0018]

As described above, according to the present invention, the energizing time to the exciting coil is shortened according to the dot density and the driving frequency is increased based on the information of the character type input to the impact type dot printer. Therefore, the higher the dot density, the lower the input energy to the exciting coil for the character type, the weaker the contact force of the printing wire, the less rebound and the better the cut of the magnetic flux, the higher the driving frequency,
This makes it possible to print such characters at the highest possible speed without interruption.

In addition, the printing power and the copying ability are reduced by weakening the contact force of the printing wire, and the character density of a character having a higher dot density is suppressed to lower the printing density so as to balance with other printing having a lower dot density. Can be taken.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an impact recording head according to an embodiment of the present invention.

FIGS. 2A and 2B are diagrams illustrating driving conditions and behavior of a printing wire when a dot density is low and when the dot density is high.

FIG. 3 is a diagram showing alphanumeric kana characters formed by the apparatus of the present invention.

FIGS. 4A and 4B are diagrams showing a difference between the density of high-quality kanji formed by the apparatus of the present invention and the density of high-quality kanji formed by a conventional apparatus.

FIG. 5 is a diagram illustrating a behavior of a printing wire when a drive frequency is increased with respect to a time of energizing an excitation coil.

[Explanation of symbols]

 3 excitation coil 5 print lever 6 print wire 10 control circuit S recording medium

Claims (1)

[Claims] 1. An impact type dot printer which magnetically attracts the print lever by selectively energizing an exciting coil and strikes a print wire integral with the print lever against a recording medium to print required characters and the like. An impact-type dot printer, further comprising control means for controlling the energizing time to the exciting coil in accordance with the dot density and increasing the driving frequency based on the input information of the character type.